The present invention relates to pager networks and more particularly to scheduling of messages in a pager network.
Prior art pager networks include multiple omnidirectional transmission sites. In many regions, the coverage areas of multiple omnidirectional transmission sites overlap. The overlapping transmission sites operate in a simulcast fashion. When one transmission site transmits a message on a particular frequency, all transmission sites transmit the same message on that frequency.
This arrangement greatly limits message carrying capacity. Across an entire region, all transmitter sites may simultaneously transmit but a single message over any particular frequency.
The assignees of the present application have developed a paging system wherein each paging transmitter may transmit disparate messages simultaneously without conflict over a plurality of directional beams, rather than omnidirectionally. Other related patent applications include VERSATILE ANTENNA ARRAY FOR MULTIPLE PENCIL BEAMS AND EFFICIENT BEAM COMBINATIONS, U.S. Pat. No. 5,784,031, MULTI-CHANNEL MULTI-BEAM ENCODING SYSTEM, U.S. Pat. No. 5,953,639, METHOD AND APPARATUS FOR ADAPTING OMNIDIRECTIONAL SYNCHRONOUS WIRELESS COMMUNICATIONS PROTOCOL TO SECTORIAL ENVIRONMENTS, U.S. Pat. No. 5,956,621. The contents of all of these applications is herein incorporated by reference.
Beams may conflict in this system. Adjacent beams of the same transmission site may conflict. Furthermore, to guarantee comprehensiveness of coverage, certain beams of one transmission site will necessarily overlap in coverage with beams of other transmission sites. Where beams conflict, simultaneous transmission of messages will become impossible.
Similar problems arise in the up-link portion of a two-way pager network that makes use of multiple reception beams received by multiple base stations. Simultaneous transmissions from subscriber units to one or more base stations may interfere with one another.